Tone selection in communication networks

ABSTRACT

Tones within a channel can be selected randomly and/or based on orthogonal tone selection. Random selection can include selecting tones randomly from a fixed set, which is referred to as channelized tone selection. Channelized tone selection can be chosen if a critical tone exists. Random selection can also include selecting resources randomly from the total number of resources available, which is referred to as non-channelized tone selection. Orthogonal tone selection can be chosen to mitigate the probability of receiver desensitization and/or to attempt to mitigate interference.

BACKGROUND

I. Field

The following description relates generally to wireless communicationsand more particularly to selection of tones in communication networks.

II. Background

Wireless communication systems are widely deployed to provide varioustypes of communication. For example, voice, data, video and so forth canbe provided through wireless communication systems. A typical wirelesscommunication system, or network, can provide multiple users access toone or more shared resources. For instance, a system may use a varietyof multiple access techniques such as Frequency Division Multiplexing(FDM), Time Division Multiplexing (TDM), Code Division Multiplexing(CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others.

Wireless communication networks are commonly utilized to communicateinformation regardless of where a user is located (inside or outside astructure) and whether a user is stationary or moving (e.g., in avehicle, walking). Generally, wireless communication networks areestablished through a mobile device communicating with a base station oraccess point. The access point covers a geographic range or cell and, asthe mobile device is operated, the mobile device can be moved in and outof these geographic cells.

A network can also be constructed utilizing solely peer-to-peer deviceswithout utilizing access points or the network can include both accesspoints (infrastructure mode) and peer-to-peer devices. These types ofnetworks are sometimes referred to as ad hoc networks. Ad hoc networkscan be self-configuring whereby when a mobile device (or access point)receives communication from another mobile device, the other mobiledevice is added to the network. As mobile devices leave the area, theyare dynamically removed from the network. Thus, the topography of thenetwork can be constantly changing.

At times, some transmission links (e.g., communications between devices)might experience interference, which at times might be stronginterference, from other transmission links. This interference can becaused by the random deployment that exists in ad hoc networks. Forexample, in a peer-to-peer ad hoc network, there is no central authority(e.g., base station) that transmits broadcast signals. Thus,synchronization is performed in an informal manner by the devices withinthe peer-to-peer network. Therefore, a problem with peer-to-peer ad hocnetworks is interference.

In typical wide-area cellular wireless systems, the interferenceobserved persists for a period of time and comes from severalinterferers with no single interferer being overly dominant. Aspects ofthe interferers make them appear as white Gaussian noise at a receiver,which can be accounted for by using techniques such as linear filtering.Increasingly deployed are ad hoc networks (e.g., hot-spots, home basestations, Femto cells, peer-to-peer, etc.), which facilitate directdevice communication without consideration of whether there is a moreoptimal serving link as in typical wide-area cellular wirelessdeployments. Because more optimal serving links can exist without beingutilized in the ad hoc deployments, there is a much greater likelihoodof dominant interference from the more optimal serving link (or to themore optimal serving link).

Typically, in infrastructure networks, mobile devices search and connectto the best (from a radio link quality or load perspective) base station(also referred to as access point). However, in peer-to-peer or otherapplications, such as home base stations (also called Femto cells), adevice connects directly to the device it desires to communicate with(peer-to-peer) or is allowed to communicate with (e.g. home basestation/Femto cell scenario). This constraint, sometimes calledrestricted association, can give rise to much stronger interference thanmight be observed in conventional infrastructure-based cellularnetworks.

SUMMARY

The following presents a simplified summary in order to provide a basicunderstanding of some aspects of the disclosed aspects. This summary isnot an extensive overview and is intended to neither identify key orcritical elements nor delineate the scope of such aspects. Its purposeis to present some concepts of the described features in a simplifiedform as a prelude to the more detailed description that is presentedlater.

In accordance with one or more features and corresponding disclosurethereof, various aspects are described in connection with tone selectionin a communication network. The tones can be selected randomly, based ona channelized scheme and/or based on a non-channelized scheme. Inaccordance with some aspects, the tones are selected based on orthogonaltone selection.

An aspect relates to a method for selecting tones in a communicationnetwork. The method includes determining if at least one tone containscritical information and selecting tones in a channel based on thedetermination. The method also includes transmitting on the selectedtones in the channel.

Another aspect relates to a wireless communications apparatus thatincludes a memory and the processor. The memory retains instructionsrelated to determining if at least one tone contains criticalinformation, selecting tones in a channel based on the determination,and transmitting on the selected tones in the channel. The processor iscoupled to the memory and is configured to execute the instructionsretained in the memory.

Still another aspect relates to a communications apparatus that includesa means for determining if at least one tone contains criticalinformation. The apparatus also includes a means for selecting tones ina channel based on the determination and a means for transmitting on theselected tones in the channel.

Yet another aspect relates to a computer program product for toneselection comprising a computer-readable medium that includes a firstset of codes for causing a computer to determine if at least one tonecontains critical information. The computer-readable medium alsoincludes a second set of codes for causing the computer to select tonesin a channel based on the determination and a third set of codes forcausing the computer to transmit on the selected tones in the channel.

Still another aspect relates to at least one processor configured forselecting tones in a communication network. The processor includes afirst module for determining if at least one tone contains criticalinformation and a second module for selecting tones in a channel basedon the determination. The processor also includes a third module fortransmitting on the selected tones in the channel.

Another aspect relates to a method for selecting tones in acommunication network. The method includes receiving informationrelating to a first channel used by at least one neighboring device andselectively choosing at least one tone with a smallest interference andnoise power based in part on the received information. The method alsoincludes using the at least one tone with the smallest interference andnoise power to form a second channel and selecting the second channel tocommunicate with at least one neighboring device within thecommunication network.

Still another aspect relates to a wireless communications apparatus thatincludes a processor and a memory. The processor is coupled to thememory and is configured to execute the instructions retained in thememory. The memory retains instructions related to receiving informationrelating to a first channel used by at least one neighboring device andselectively choosing at least one tone with a smallest interference andnoise power. The memory also retains instructions related to using theat least one tone with the smallest interference and noise power to forma second channel and selecting the second channel to communicate withthe at least one neighboring device within the communication network.

A further aspect relates to a communications apparatus comprising ameans for receiving information relating to a first channel used by atleast one neighboring device and a means for choosing at least one tonewith a smallest interference and noise power. The communicationsapparatus also includes a means for using the at least one tone with thesmallest interference and noise power to form a second channel and ameans for selecting the second channel to communicate with the at leastone neighboring device within the communication network.

Yet another aspect relates to a computer program product for selectingtones in a communication network. The computer program product includesa computer-readable medium that includes a first set of codes forcausing a computer to receive information relating to a first channelused by at least one neighboring device and a second set of codes forcausing the computer to choose at least one tone with a smallestinterference and noise power. The computer-readable medium also includesa third set of codes for causing the computer to utilize the at leastone tone with the smallest interference and noise power to form a secondchannel. A fourth set of codes for causing the computer to choose thesecond channel to communicate with the at least one neighboring devicewithin the communication network is also included.

A further aspect relates to at least one processor configured to providetone selection. The processor includes a first module for receivinginformation relating to a first channel used by at least one neighboringdevice and a second module for choosing at least one tone with asmallest interference and noise power. The at least one tone does notcause excessive interference to the at least one neighboring devicewithin the communication network. The processor also includes a thirdmodule for using the at least one tone with the smallest interferenceand noise power to form a second channel and a fourth module forselecting the second channel to communicate with the at least oneneighboring device within the communication network.

To the accomplishment of the foregoing and related ends, one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative aspectsand are indicative of but a few of the various ways in which theprinciples of the features may be employed. Other advantages and novelfeatures will become apparent from the following detailed descriptionwhen considered in conjunction with the drawings and the disclosedexamples are intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a wireless communication network in accordance withvarious aspects presented herein.

FIG. 2 illustrates an example of an OFDM control channel.

FIG. 3 illustrates a simple two-link peer-to-peer network.

FIG. 4 illustrates a system for tone selection in a communicationsnetwork.

FIG. 5 illustrates an example of channelized tone selection.

FIG. 6 illustrates an example of non-channelized tone selection.

FIG. 7 illustrates a method for random tone selection.

FIG. 8 illustrates a method for orthogonal tone selection.

FIG. 9 illustrates a system that facilitates tone selection in awireless communication environment in accordance with one or more of thedisclosed embodiments.

FIG. 10 illustrates a system that facilitates tone selection within apeer-to-peer ad hoc wireless communication environment in accordancewith one or more of the disclosed embodiments.

FIG. 11 illustrates an example system that facilitates random toneselection in a communication network.

FIG. 12 illustrates an example system that facilitates orthogonal toneselection in a communication network.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that such features(s)may be practiced without these specific details. In other instances,well-known structures and devices are shown in block diagram form inorder to facilitate describing these features.

As used in this application, the terms “component”, “module”, “system”,and the like are intended to refer to a computer-related entity, eitherhardware, firmware, a combination of hardware and software, software, orsoftware in execution. For example, a component may be, but is notlimited to being, a process running on a processor, a processor, anobject, an executable, a thread of execution, a program, and/or acomputer. By way of illustration, both an application running on acomputing device and the computing device can be a component. One ormore components can reside within a process and/or thread of executionand a component may be localized on one computer and/or distributedbetween two or more computers. In addition, these components can executefrom various computer readable media having various data structuresstored thereon. The components may communicate by way of local and/orremote processes such as in accordance with a signal having one or moredata packets (e.g., data from one component interacting with anothercomponent in a local system, distributed system, and/or across a networksuch as the Internet with other systems by way of the signal).

Furthermore, various examples are described herein in connection with awireless terminal. A wireless terminal can also be called a system,subscriber unit, subscriber station, mobile station, mobile device,mobile, remote station, remote terminal, access terminal, user terminal,terminal, wireless communication device, user agent, user device, oruser equipment (UE). A wireless terminal may be a cellular telephone, asmart phone, a cordless telephone, a Session Initiation Protocol (SIP)phone, a wireless local loop (WLL) station, a personal digital assistant(PDA), a handheld device having wireless connection capability, alaptop, a handheld computing device, a satellite radio, a globalpositioning system, a node, and/or a processing device connected to awireless modem.

Various aspects or features will be presented in terms of systems thatmay include a number of devices, components, modules, and the like. Itis to be understood and appreciated that the various systems may includeadditional devices, components, modules, etc. and/or may not include allof the devices, components, modules etc. discussed in connection withthe figures. A combination of these approaches may also be used.

Referring now to FIG. 1, a wireless communication system 100 isillustrated in accordance with various aspects presented herein. System100 comprises a base station 102 that can include multiple antennagroups. For example, one antenna group can include antennas 104 and 106,another group can comprise antennas 108 and 110, and an additional groupcan include antennas 112 and 114. Two antennas are illustrated for eachantenna group; however, more or fewer antennas can be utilized for eachgroup. Base station 102 can additionally include a transmitter chain anda receiver chain, each of which can in turn comprise a multitude ofcomponents associated with signal transmission and reception (e.g.,processors, modulators, multiplexers, demodulators, demultiplexers,antennas, etc.), as will be appreciated by one skilled in the art.Additionally, the base station 102 can be a home base station, a Femtobase station, and/or the like.

Base station 102 can communicate with one or more mobile devices such asmobile device 116; however, it is to be appreciated that base station102 can communicate with substantially any number of mobile devicessimilar to mobile device 116. As depicted, mobile device 116 is incommunication with antennas 104 and 106, where antennas 104 and 106transmit information to mobile device 116 over a forward link 118 andreceive information from mobile device 116 over a reverse link 120.

In addition, mobile devices 122 and 128 can be communicating with oneanother, such as in a peer-to-peer configuration. Moreover, mobiledevice 122 is in communication with mobile device 128 using similarlinks 124 and 126. In a frequency division duplex (FDD) system, forwardlink 118 can utilize a different frequency band than that used byreverse link 120, for example. Further, in a time division duplex (TDD)system, forward link 118 and reverse link 120 can utilize a commonfrequency band.

In a peer-to-peer ad hoc network, devices within range of each other,such as devices 122 and 128, communicate directly with each otherwithout a base station 102 and/or a wired infrastructure to relay theircommunication. Additionally, peer devices or nodes can relay traffic.The devices within the network communicating in a peer-to-peer mannercan function similar to base stations and relay traffic orcommunications to other devices, functioning similar to base stations,until the traffic reaches its ultimate destination. The devices can alsotransmit control channels, which carry information that can be utilizedto manage the data transmission between peer nodes.

A communication network can include any number of mobile devices ornodes that are in wireless communication. Each node can be within rangeof one or more other nodes and can communicate with the other nodes orthrough utilization of the other nodes, such as in a multi-hoptopography (e.g., communications can hop from node to node untilreaching a final destination). For example, a sender node may wish tocommunicate with a receiver node. To enable packet transfer betweensender node and receiver node, one or more intermediate nodes can beutilized. It should be understood that any node can be a sender nodeand/or a receiver node and can perform functions of either sendingand/or receiving information at substantially the same time (e.g., canbroadcast or communicate information at about the same time as receivinginformation).

Any node within network can transmit channel information. The nodes canbe configured to selectively choose tones in a channel in peer-to-peerad hoc type networks and each node can include a memory and a processor,coupled to the memory, configured to execute the instructions retainedin the memory. It should be noted that the aspects disclosed herein maydiscuss tone selection in control channels based on Orthogonal FrequencyDivision Multiplexing (OFDM) signaling, however other techniques can beutilized with the disclosed aspects. Additionally, although the variousaspects may be described with reference to a control channel, thevarious aspects can be applied to other types of channels. In OFDMsignaling, each node utilizes one set of tones to transmit the necessarycontrolling information for the data transmission (e.g., request totransmit, grant to transmit). In peer-to-peer ad hoc type networks,there is no center base station (e.g., no access point) and each nodecan communicate with its peer node when there is a data burst.Therefore, prior to the data transmission a channel can be utilized tomanage the data transmission between peer nodes and other competinglinks sharing the medium. The channel, which can be a control channel,may be utilized by the transmitting peer node that desires to transmitand explicitly or implicitly identify to whom it wishes to transmit. Thechannel may include some attributes of the desired transmission (e.g.,the Quality of Service (QoS)). Similarly, on the channel, the receivingpeer node may acknowledge receipt of the transmitter's request andprovide some information on how to transmit.

Among a set of links competing for a shared medium in the absence of acentral coordinator, such as a base station, each transmitter (receiver)should select a set of tones from a common pool in order to conduct itscommunication on the control channel. To facilitate tone selection inthe control channel of peer-to-peer ad hoc networks, each node canemploy random tone selection and/or orthogonal tone selection. Randomtone selection means that from the total set of available tones forcontrol, each node randomly chooses a certain number of tones totransmit its signal. The selection of tones can be performed in apseudo-random fashion utilizing a common notion of system time (e.g.,from a GPS or other external source) and source/destination nodeidentity to determine which tones to select. Random selection caninclude channelized tone selection or non-channelized tone selection.Channelized tone selection can be chosen if one or more critical tonesexist (such as a pilot tone). A critical tone is one which, ifinterfered with, can cause the transmission to fail, even if the othertones that constitute the control transmission are not interfered with.If a critical tone does not exist, non-channelized tone selection can bechosen as it provides the least constraint on resource selection fromthe common space, which can improve the communication performance of thedevices (by mitigating the probability of multiple nodes selecting thesame resource).

Channelized tone selection will now be described with reference to thefollowing example. In this example, the total control space comprises 32tones and 8 symbols. Furthermore, a control transmission, in thisexample, requires the selection of 4 tones. In channelized toneselection, the space of 256 tones is divided in a pre-determined mannerinto 64 choices and a node picks one of the 64 at random. On the otherhand, for non-channelized, random selection, any choice of 4 tones outof the space of 256 tones is allowed, which allows a large set ofchoices.

When utilizing orthogonal selection, the selection of tones can be madebased on the tones with the smallest interference and noise power. Inaccordance with some aspects, during orthogonal selection, the selectionof tones can be made based on the symbol with the smallest totalinterference power and then the tones with the smallest interferencepower within the selected symbol are the tones chosen for the controlchannel. Channelized tone selection may be suitable for the orthogonalselection case. Further information relating to random tone selectionand orthogonal tone selection are provided below.

FIG. 2 illustrates an example of an OFDM control channel 200, however,other types of channels can be utilized with the disclosed aspects. Acontrol channel 200 is a logical channel that carries signalinginformation typically utilized to establish and control voice or datacommunications. In a peer-to-peer ad hoc network, the control channelcontains information relating to how peer devices can establishcommunication with the device sending the control channel information.Devices within the vicinity monitor the information within the controlchannel, and based on the information, can establish communications withthe transmitting device.

As illustrated, the horizontal axis 202 represents time and the verticalaxis 204 represents frequency. Each vertical column represents an OFDMsymbol and each row represents a frequency tone. The illustrated controlchannel 200 contains eight OFDM symbols, each having 16 tones, indexedas 1, 2, . . . , 16. Each small box represents a tone-symbol, which is asingle tone over a single transmission symbol period. Control channel200 includes signals, which are transmitted sequentially over time. Asignal includes one or more (e.g. a small number) symbols.

In the illustrated example, four OFDM symbols are used for “Request” fortransmission (sent by the transmitter to request to be scheduled by thereceiver) and four OFDM symbols are used for “Grant” of transmission(sent by the receiver as acknowledging the request and asking thetransmitter to go ahead). This can assume that each link uses four toneswithin the same symbol to convey the information of “Request” and“Grant”. Within these four tones, one tone can be used for pilot andthree tones can be used for request/grant information (e.g., usingQuadrature Phase Shift Keying (QPSK) modulation and convey six coded oruncoded bits). It should be noted that the disclosed aspects could beutilized in other contexts, wherein the above described assumption canbe relaxed and applied in a general context. For example, the four tonesneed not be on the same OFDM symbol.

FIG. 3 illustrates a simple two-link peer-to-peer network 300 in whichNode “A” 302 transmits to Node “B” 304 and Node “C” 306 transmits toNode “D” 308. The communication path between the nodes is referred to asa “link”. It should be noted that this figure is for illustrationpurposes only and other links, which can be more complex, can beutilized with the disclosed techniques. Additionally, Nodes “A”, “B”,“C”, and/or “D” 302-308 can utilize different types of configurations,including a configuration similar to the wireless communications network100 of FIG. 1.

Peer-to-peer networks do not rely on the presence of an access point,therefore there are no broadcast signals being sent by a centralauthority. Thus, each device transmits information that allows othersdevices that receive the transmission to establish communication with(or through) the sending device, if desired. Interference within thenetwork might cause issues as it relates to tone selection and thesuccessful transmission of tones within a control channel. For example,if one or more of the tones contain important information, interferencemight cause that important tone to not be received at the peer nodes.The important tones are those tones that are necessary for thecommunication and reception process, such as a pilot tone. If theimportant tones are not received due to interference or othercommunication failures, communication cannot be established with thenode sending the control channel information.

With reference now to FIGS. 2 and 3, the following example is forillustration purposes and to further the understanding of the disclosedaspects. Node “A” 302 can send a “Request” for transmission to Node “B”304 to establish communications between the nodes, which is illustratedby the four OFDM symbols at 206. Node “B” 304 can reply to Node “A” 302with a “Grant”, which is illustrated by the four OFDM symbols at 208.Similarly, Node “C” 306 can send a “Request” to Node “D” 308,illustrated by the four OFDM symbols at 210. Node “D” 308 can reply witha “Grant”, illustrated by the four OFDM symbols at 212. It should benoted that although the figure illustrates the Grant and Requests in thesame tone location on different symbols, the aspects are no so limitedand the Grants and/or Requests can be in different tone locations ondifferent symbols.

Since the control channel 200 is utilized in a peer-to-peer ad hocnetwork, there is no central authority (e.g., access point) to establishthe communications between the nodes. Therefore, although illustratedand described as a selection of different tones and different symbols bythe two links, there is the chance that these tones and symbols mightcollide if the same tones were selected by the links. If there is acollision in this example, the collision will be across all four tones(or other selected number of tones). If one or more of the tones containimportant information needed to establish or aid reception of thecommunications (e.g., pilot tones), there might be a communicationfailure. Thus, the disclosed aspects provide a scheme to mitigate theprobability of collision of one or more tones.

FIG. 4 illustrates a system 400 for tone selection in a peer-to-peercommunications network for a more reliable channel. System 400 canreside, for example, in a device 402. A problem associated with toneselection in peer-to-peer networks is interference avoidance since, inad hoc networks, one transmission link may experience very stronginterference from some other link due to the random deployment andrestricted association in ad hoc networks. The strong interference candestroy the decoding procedure or desense (e.g., desensitize a receiver)the corresponding symbol. In the desense case, the interference can beso strong that even if the different tones on the same symbol areutilized, reception may be difficult. In this case, it might be thatonly separation in time will mitigate the interference.

Device 402 can include a random tone selector 404 that can be configuredto determine whether to choose tones in a channel randomly. When a nodeor device 402 does not have information regarding possible interference,the tone selection can be performed randomly. There are at least twooptions with random tone selection: channelized tone selection(channelized functionality 406) and non-channelized tone selection(non-channelized functionality 408). Random tone selector 404, can beconfigured to choose channelized tone selection and/or non-channelizedtone selection, depending on the existence of a critical tone, such as apilot tone. Non-channelized or channelized tone selection is a longtime-scale design decision and selecting tones randomly is a shorttime-scale design decision.

In channelized tone selection, the definition of tone sets, each ofwhich can comprise four tones, is common for all links. Therefore, alink experiences similar interference on all four tones. The channelsare selected randomly. FIG. 5 illustrates an example of channelized toneselection 500. The horizontal axis 502 represents time and the verticalaxis 504 represents frequency. In the channelized case 500, in eachsymbol, tone sets {1, 2, 3, 4} and {5, 6, 7, 8} are defined as differentchannels, which can be occupied by link A-B and link C-D, respectively.

Thus, random tone selector 404, utilizing channelized functionality 406,can select four tones that are contiguous and can be chosen randomlyfrom a fixed set. In one embodiment, the sequence and combination of thetones defines the signature of device 402. The receiving device or node(not shown) receives information from the location of the tones andlooks for energy on the tones associated with the signature of thesending device (e.g., device 402). These tones can be selected randomly.However, if there is a collision, the collision occurs on all four tonesand the receiving device will not receive the communication, or willreceive the communication with interference.

Thus, in some cases, non-channelized tone selection might be chosen byrandom tone selector 404. In non-channelized tone selection, the tonesare selected in a completely random way. Therefore, a link mayexperience different interference on the four tones or, stateddifferently, collisions could be limited to a subset of the tones usedby a transmitting node and/or a receiving node. FIG. 6 illustrates anexample of non-channelized tone selection 600. The horizontal axis 602represents time and the vertical axis 604 represents frequency. Duringnon-channelized tone selection, random tone selector 404, throughnon-channelized functionality 408, selects four tones (at random) out ofthe total number of tones available (e.g., 256 tones). It should benoted that although the tones illustrated are on the same OFDM channel,the disclosed aspects are not so limited.

Through utilization of non-channelized tone selection, the probabilityof a collision on each of the four tones can be mitigated. Since, theprobability of colliding on every tone chosen by non-channelizationfunctionality 406 is smaller than the probability of collision on everytone chosen by channelization functionality 408, random tone selector402 might utilize the non-channelized functionality 408 if a pilot tone(or a critical tone) is not included as one or more of the four tones.For example, non-channelized random tone selection may be utilized inthe case of non-coherent communication or if a pilot is provided in someother fashion outside of the four tones. The pilot tone can be providedfor coherent demodulation.

In some situations (e.g., if no important tone exists), thenon-channelized tone selection 600 might be preferable since it canprovide more tone-symbols. In the illustrated example, for each link,there are

$\begin{matrix}\begin{pmatrix}64 \\4\end{pmatrix} & \;\end{matrix}$

possible choices for non-channelized selection. However, in channelizedselection there are only sixteen possible choices. For non-channelizedselection 600, if the information bits are coded, the codeword may stillbe recovered if a portion of the four tones collide with strongerinterferences since the likelihood of all tones experiencing collisionis low. This is not possible for channelized selection since each linkexperiences the same interference on all four tones.

When the channel is specifically known (or, as in the case ofnon-coherent communications, does not need to be specifically known),then, non-channelized tone selection can outperform channelized toneselection. However, when a pilot is used on one of the tones for channelestimation, channelized tone selection performs better thannon-channelized tone selection. The reason for this will now bedescribed.

There are four tones used for each link, m tones, n strong interferers(n<<m) for the link being studied. For this example, it is assumed thatthe decoding completely fails if the pilot collides with any stronginterferer, which in practice for the restricted association mode ofad-hoc communications, is a good assumption. Then, it can be illustratedthat the probability of pilot collision is given by the equation:

$\begin{matrix}{\left( \frac{{m/4} - 1}{m/4} \right)^{n} \approx {1 - \frac{4n}{m}}} & {{Equation}\mspace{20mu} 1}\end{matrix}$

for the channelized tone selection case and:

$\begin{matrix}{\left( \frac{m - 1}{m} \right)^{n} \approx {1 - \frac{4n}{m}}} & {{Equation}\mspace{20mu} 2}\end{matrix}$

for the non-channelized tone selection case.

Thus, as shown in Equations 1 and 2, the pilot collision probability isalmost the same for channelized tone selection and non-channelized toneselection cases. It should be noted that a decoding error event mayarise from collision on pilot or on data. However, in the channelizedtone selection case, the event of collision on a pilot is identical tothat on data since the interference on all four tones are the same forany link. This makes the probability of decoding error very close topilot collision probability. For the non-channelized tone selectioncase, these two events are not identical, thus making the probability ofdecoding error larger than pilot collision probability. Thus, thechannelized tone selection scheme can achieve a lower decoding errorrate than the non-channelized tone selection scheme.

In summary, if a pilot is used on one or more tones (or generally, onetone or more tones are critical, in the sense that once this tonecollides with strong interference, the decoding fails with highprobability), channelized tone selection is preferred. If a pilot is notused on one or more tones, non-channelized tone selection can performbetter.

Alternatively or additionally, device 402 can include an orthogonal toneselector 410 that can be configured to choose one or more tones based onan orthogonal selection. Note that in the context of random selection,for channelized or non-channelized, control channel tones selected bydifferent transmitters/receivers could end up being orthogonal, but itis not orthogonal by design or measurement as in the case of orthogonaltone selection described herein. If the link or device 402 can sense theinterference power on each tone, then the device 402 can select tonesorthogonal to the tones used by other, peer devices. In accordance withan aspect, orthogonal tone selector 410 can choose the tones having thesmallest interference power in an attempt to mitigate interference.

In accordance with other aspects, orthogonal tone selector 410 canselect the symbol having the smallest total interference and noisepower, which can help mitigate the probability of desense. Next,orthogonal tone selector 410 can select the tones with the smallestinterference and noise power within the chosen symbol, thus improvingthe chances of interference avoidance.

Orthogonal tone selector 410 can facilitate a link (or device 402)changing its tone selection to a better location if a stronginterference is detected in the current location of the selected tones.The interference can be a function of a new device recently added to thead hoc network, a change of other links (e.g., devices moving out of thenetwork, devices changing their tone selection, and so forth), or due toother factors.

With further reference to FIG. 4, system 400 can include a memory 412operatively coupled to device 402. Memory 412 can store informationrelated to tone selection, channelized tone selection, non-channelizedtone selection, link information, orthogonal selection, and othersuitable information related to selection of tones in a peer-to-peercommunication network. A processor 414 can be operatively connected todevice 402 (and/or memory 412) to facilitate analysis of informationrelated to mitigating tone selection in a communication network.Processor 414 can be a processor dedicated to analyzing and/orgenerating information received by device 402, a processor that controlsone or more components of system 400, and/or a processor that bothanalyzes and generates information received by device 402 and controlsone or more components of system 400.

Memory 412 can store protocols associated with selecting tones within achannel, mitigating interference associated with the tones, selectivelymodifying an orthogonal tone selection based on experiencedinterference, mitigating interference, detecting a pilot tone, detectinginterference, taking action to control communication such that system400 can employ stored protocols and/or algorithms to achieve improvedcommunications in a wireless network as described herein.

In accordance with some aspects, memory 412 retains instructions relatedto determining if at least one tone contains critical information,selecting tones in a channel based on the determination, andtransmitting on the selected tones in the channel. Memory 412 can alsoretain instructions related to choosing a channelized tone selection ifthe determination is that at least one tone contains criticalinformation. Additionally or alternatively, memory 412 retainsinstructions related to selecting the tones randomly from a fixed set oftones, wherein each tone comprises a channel.

According to some aspects, memory 412 retains instructions related toreceiving information related to a first channel used by at least oneneighboring device and selectively choosing at least one tone with asmallest interference and noise power. Memory 412 also retainsinstructions related to using the at least one tone with the smallestinterference and noise power to form a second channel and selecting thesecond channel to communicate with the at least one neighboring devicewithin the communication network. According to some aspects, memory 412further retains instructions relating to selecting the at least one tonethat does not cause excessive interference to the at least oneneighboring device within the communication network. Memory 412 may alsoretain instructions related to identifying a symbol with the smallesttotal interference power, identifying one or more tones with thesmallest interference power, the one or more tones are included in theidentified symbol, and using the identified one or more tones in thesecond channel. According to some aspects, memory 412 retainsinstructions related to observing interference in the network,determining if there is strong interference experienced on the at leastone tone used in the channel, and selectively changing the at least onetone used in the channel if strong interference is experienced.

It should be appreciated that the data store (e.g., memories) componentsdescribed herein can be either volatile memory or nonvolatile memory, orcan include both volatile and nonvolatile memory. By way of example andnot limitation, nonvolatile memory can include read only memory (ROM),programmable ROM (PROM), electrically programmable ROM (EPROM),electrically erasable ROM (EEPROM), or flash memory. Volatile memory caninclude random access memory (RAM), which acts as external cache memory.By way of example and not limitation, RAM is available in many formssuch as synchronous RAM (DRAM), dynamic RAM (DRAM), synchronous DRAM(SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM),Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM). Memory 412 ofthe disclosed embodiments are intended to comprise, without beinglimited to, these and other suitable types of memory.

In view of the exemplary systems shown and described above,methodologies that may be implemented in accordance with the disclosedsubject matter, will be better appreciated with reference to thefollowing flow charts. While, for purposes of simplicity of explanation,the methodologies are shown and described as a series of blocks, it isto be understood and appreciated that the claimed subject matter is notlimited by the number or order of blocks, as some blocks may occur indifferent orders and/or concurrently with other blocks from what isdepicted and described herein. Moreover, not all illustrated blocks maybe required to implement the methodologies described hereinafter. It isto be appreciated that the functionality associated with the blocks maybe implemented by software, hardware, a combination thereof or any othersuitable means (e.g. device, system, process, component). Additionally,it should be further appreciated that the methodologies disclosedhereinafter and throughout this specification are capable of beingstored on an article of manufacture to facilitate transporting andtransferring such methodologies to various devices. Those skilled in theart will understand and appreciate that a methodology couldalternatively be represented as a series of interrelated states orevents, such as in a state diagram.

FIG. 7 illustrates a method 700 for random tone selection in a controlchannel. Random selection includes channelized tone selection and/ornon-channelized tone selection. Channelized tone selection can beutilized is a critical tone exists. If a critical tone does not exist,then non-channelized tone selection can be utilized. Method 700 starts,at 702, when a channel is to be sent within a peer-to-peer ad hocnetwork. For example, a control channel can be sent that carriesinformation that can be utilized by other, peer devices within thepeer-to-peer ad hoc network to communicate with the sending device.

In order to select the tones in the control channel, a determination ismade, at 704, whether a critical tone, such as pilot tone, is beingsent. In accordance with some aspects, the at least one critical tone isa pilot tone for coherent demodulation. If there is a critical tone(“YES”), method 700 continues, at 706, and channelized tone selection ischosen. Channelized tone selection comprises selecting one channel froma set of pre-defined channels, wherein each channel comprises at leastone tone. The tones can be selected randomly from a fixed set of tones,wherein each tone comprises a channel. In accordance with some aspects,in channelized tone selection, contiguous tones are selected.

If the determination, at 704, is that a critical tone does not exist,then at 708, non-channelized tone selection can be chosen. Thenon-channelized tone selection can be a long time-scale design decision.In non-channelized tone selection, the tones can be chosen randomly froma total number of tones available. Selecting the tones randomly can be ashort time-scale design decision. The tones chosen by non-channelizedtone selection can be contiguous, non-contiguous, or combinationsthereof. It should be noted that, in accordance with some aspects,channelized tone selection can be chosen even if critical tones do notexist.

FIG. 8 illustrates a method 800 for orthogonal tone selection in acontrol channel. Method 800 starts, at 802, when orthogonal toneselection is chosen. There are at least two methods of choosing tones inan orthogonal tone selection scheme. In the first method, the tones withthe smallest interference and noise power are identified, at 804, whichcan mitigate the probability of desense. In a second method, the symbolwith the smallest total interference power is identified, at 806. At808, the tones with the smallest power within the chosen symbol areidentified, which can help achieve interference avoidance. At 810,regardless of the method utilized to choose the tones, the tonesidentified, at 804 and/or 808, are selected to constitute the controlchannel.

In accordance with some aspects, a strong interference might bedetected, at 812. This interference can be caused by a new deviceentering the peer-to-peer network, a change in other links, or based onother factors. If interference is detected, at 814 the tone selection ischanged to a better location (e.g. a location with less interference).The tone selection can be changed in an orthogonal manner or in a randommanner. The tone selection can be changed any number of times based onthe observed performance.

FIG. 9 illustrates a method 900 for selecting tones in a communicationnetwork. At 902, information related to a first channel used by at leastone neighboring device is received. At least one tone with a smallestinterference and noise power is selectively chosen, at 904. The choiceis made based on the received information. At 906, the tone(s) with thesmallest interference and noise power are utilized to form a secondchannel. At 908, the second channel is selected to communicate with theneighboring device(s).

In accordance with some aspects, the tone can be chosen by selectingthat at least one tone that does not cause excessive interference to theneighboring device(s). According to some aspects, choosing the toneincludes identifying a symbol with the smallest total interference powerand identifying one or more tones, included in the identified symbols,with the smallest interference power. The identified one or more tonesare utilized to form the second channel. The tone(s) can be from thesame symbol.

With reference now to FIG. 10, illustrated is a system 1000 thatfacilitates tone selection in a control channel within a peer-to-peer adhoc wireless communication environment in accordance with one or more ofthe disclosed embodiments. System 1000 can reside in a user device.System 1000 comprises a receiver 1002 that can receive a signal from,for example, a receiver antenna. The receiver 1002 can perform typicalactions thereon, such as filtering, amplifying, etc. the receivedsignal. The receiver 1002 can also digitize the signal to obtainsamples. A demodulator 1004 can retrieve information bits from thereceived signals and provide them to a processor 1006.

Processor 1006 can be a processor dedicated to analyzing informationreceived by receiver component 1002 and/or generating information fortransmission by a transmitter 1012, such as a control channel.Additionally or alternatively, processor 1006 can control one or morecomponents of user device 1000, analyze information received by receiver1002, generate information for transmission by transmitter 1016, and/orcontrol one or more components of user device 1000. Processor 1006 mayinclude a controller component capable of coordinating communicationswith additional user devices.

User device 1000 can additionally comprise memory 1008 operativelycoupled to processor 1006 and that can store information related tocoordinating communications and any other suitable information. Memory1008 can additionally store protocols associated with coordinatingcommunication and/or selecting tones in a control channel. User device1000 can further comprise a symbol modulator 1010 and a transmitter 1012that transmits the modulated signal.

With reference to FIG. 11, illustrated is an example system 1100 thatfacilitates random tone selection in a communication network. System1100 is represented as including functional blocks, which may befunctional blocks that represent functions implemented by a processor,software, or combination thereof (e.g., firmware).

System 1100 includes a logical grouping 1102 of electrical componentsthat can act separately or in conjunction. Logical grouping 1102includes an electrical component 1104 for determining if at least onetone contains critical information. The critical information can be apilot tone. Also included in logical grouping 1102 is an electricalcomponent 1106 for selecting tones in a channel based on thedetermination of whether at least one tone contains criticalinformation. In accordance with some aspects, the selection of the tonesin the channel is performed randomly. According to some aspects, anon-channelized tone selection is chosen if the determination byelectrical component 1104 is that at least one tone does not containcritical information. The tones can be selected randomly from a totalnumber of tones available. Logical grouping 1102 also includes anelectrical component 1108 for transmitting on the selected tones in thechannel.

In accordance with some aspects, logical grouping 1102 also includes anelectrical component for choosing a channelized tone selection if thedetermination is that at least one tone contains critical information.The channelized tone selection can include selecting the channel from aset of pre-defined channels. Each channel can include at least one tone.The tone can be selected from the pre-defined set randomly from a fixedset of tones, wherein each tone comprises a channel. The selection canbe based on at least one of a system time, a node identity, orcombinations thereof.

A random channelized scheme is utilized or a random non-channelizedscheme is utilized. In a random channelized scheme, if one toneexperiences interference, generally all the tones that constitute achannel will experience interference. In a random non-channelizedscheme, there is diversity and the transmission is encoded over all thetones. In the random non-channelized scheme, the likelihood of all tonesexperiencing interference is low and, if a tone does experienceinterference, the remaining tones can be utilized to decode the message.If there is a critical tone, such as a tone that includes a pilotsymbol, then the random channelized scheme should be chosen.

Additionally, system 1100 can include a memory 1110 that retainsinstructions for executing functions associated with electricalcomponents 1104, 1106, and 1108 or other components. While shown asbeing external to memory 1110, it is to be understood that one or moreof electrical components 1104, 1106, and 1008 may exist within memory1110.

FIG. 12 illustrates an example system 1200 that facilitates orthogonaltone selection in a communication network. System 1200 is represented asincluding functional blocks, which may be functional blocks thatrepresent functions implemented by a processor, software, or combinationthereof (e.g., firmware). System 1200 includes a logical grouping 1202of electrical components that can act separately or in conjunction.Logical grouping 1202 includes an electrical component 1204 forreceiving information related to a first channel used by at least oneneighboring device.

Logical grouping 1202 also includes an electrical component 1206 forchoosing at least one tone with a smallest interference and noise power.Electrical component 1206 can also select the at least one tone thatdoes not cause excessive interference to the at least one neighboringdevice within the communication network. Additionally or alternatively,electrical component 1206 can identify a symbol with the smallest totalinterference power, identify one or more tones with the smallestinterference power, and utilize the identified one or more tones in thesecond channel. The one or more tones are included in the identifiedsymbol.

Also included in logical grouping 1202 is an electrical component 1208for using the at least one tone with the smallest interference and noisepower to form a second channel. Further, logical grouping 1202 includesan electrical component 1210 for selecting the second channel tocommunicate with the at least one neighboring device within thecommunication network.

Additionally, system 1200 can include a memory 1212 that retainsinstructions for executing functions associated with electricalcomponents 1204, 1206, 1208, and 1210 or other components. While shownas being external to memory 1212, it is to be understood that one ormore of electrical components 1204, 1206, 1208, and 1210 may existwithin memory 1212.

It is to be understood that the aspects described herein may beimplemented by hardware, software, firmware or any combination thereof.When implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by ageneral purpose or special purpose computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code means in the form of instructions or datastructures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

The various illustrative logics, logical blocks, modules, and circuitsdescribed in connection with the aspects disclosed herein may beimplemented or performed with a general purpose processor, a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a field programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but, in the alternative, the processor may be any conventionalprocessor, controller, microcontroller, or state machine. A processormay also be implemented as a combination of computing devices, e.g., acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. Additionally, at least oneprocessor may comprise one or more modules operable to perform one ormore of the steps and/or actions described above.

For a software implementation, the techniques described herein may beimplemented with modules (e.g., procedures, functions, and so on) thatperform the functions described herein. The software codes may be storedin memory units and executed by processors. The memory unit may beimplemented within the processor or external to the processor, in whichcase it can be communicatively coupled to the processor through variousmeans as is known in the art. Further, at least one processor mayinclude one or more modules operable to perform the functions describedherein.

The techniques described herein may be used for various wirelesscommunication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and othersystems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includesWideband-CDMA (W-CDMA) and other variants of CDMA. Further,CDMA2000covers IS-2000, IS-95 and IS-856 standards. A TDMA system mayimplement a radio technology such as Global System for MobileCommunications (GSM). An OFDMA system may implement a radio technologysuch as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc. UTRA andE-UTRA are part of Universal Mobile Telecommunication System (UMTS).3GPP Long Term Evolution (LTE) is a release of UMTS that uses E-UTRA,which employs OFDMA on the downlink and SC-FDMA on the uplink. UTRA,E-UTRA, UMTS, LTE and GSM are described in documents from anorganization named “3rd Generation Partnership Project” (3GPP).Additionally, CDMA2000and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2).Further, such wireless communication systems may additionally includepeer-to-peer (e.g., mobile-to-mobile) ad hoc network systems often usingunpaired unlicensed spectrums, 802.xx wireless LAN, BLUETOOTH and anyother short- or long-range, wireless communication techniques.

Moreover, various aspects or features described herein may beimplemented as a method, apparatus, or article of manufacture usingstandard programming and/or engineering techniques. The term “article ofmanufacture” as used herein is intended to encompass a computer programaccessible from any computer-readable device, carrier, or media. Forexample, computer-readable media can include but are not limited tomagnetic storage devices (e.g., hard disk, floppy disk, magnetic strips,etc.), optical disks (e.g., compact disk (CD), digital versatile disk(DVD), etc.), smart cards, and flash memory devices (e.g., EPROM, card,stick, key drive, etc.). Additionally, various storage media describedherein can represent one or more devices and/or other machine-readablemedia for storing information. The term “machine-readable medium” caninclude, without being limited to, wireless channels and various othermedia capable of storing, containing, and/or carrying instruction(s)and/or data. Additionally, a computer program product may include acomputer readable medium having one or more instructions or codesoperable to cause a computer to perform the functions described herein.

Further, the steps and/or actions of a method or algorithm described inconnection with the aspects disclosed herein may be embodied directly inhardware, in a software module executed by a processor, or in acombination of the two. A software module may reside in RAM memory,flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a harddisk, a removable disk, a CD-ROM, or any other form of storage mediumknown in the art. An exemplary storage medium may be coupled to theprocessor, such that the processor can read information from, and writeinformation to, the storage medium. In the alternative, the storagemedium may be integral to the processor. Further, in some aspects, theprocessor and the storage medium may reside in an ASIC. Additionally,the ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components in auser terminal. Additionally, in some aspects, the steps and/or actionsof a method or algorithm may reside as one or any combination or set ofcodes and/or instructions on a machine readable medium and/or computerreadable medium, which may be incorporated into a computer programproduct.

While the foregoing disclosure discusses illustrative aspects and/oraspects, it should be noted that various changes and modifications couldbe made herein without departing from the scope of the described aspectsand/or aspects as defined by the appended claims. Accordingly, thedescribed aspects are intended to embrace all such alterations,modifications and variations that fall within scope of the appendedclaims. Furthermore, although elements of the described aspects and/oraspects may be described or claimed in the singular, the plural iscontemplated unless limitation to the singular is explicitly stated.Additionally, all or a portion of any aspect and/or aspect may beutilized with all or a portion of any other aspect and/or aspect, unlessstated otherwise.

To the extent that the term “includes” is used in either the detaileddescription or the claims, such term is intended to be inclusive in amanner similar to the term “comprising” as “comprising” is interpretedwhen employed as a transitional word in a claim. Furthermore, the term“or” as used in either the detailed description of the claims is meantto be a “non-exclusive or”.

1. A method for selecting tones in a communication network, comprising:determining if at least one tone contains critical information;selecting tones in a channel based on the determination; andtransmitting on the selected tones in the channel.
 2. The method claim1, further comprises choosing a channelized tone selection if thedetermination is that at least one tone contains critical information.3. The method of claim 2, wherein choosing a channelized tone selectioncomprises selecting the channel from a set of pre-defined channels,wherein each channel comprises at least one tone.
 4. The method of claim3, further comprises selecting the tones from the pre-defined set ofchannels randomly from a fixed set of tones, wherein each tone comprisesa channel.
 5. The method of claim 4, wherein the selection is based onat least one of system time, node identity, or combinations thereof. 6.The method claim 1, further comprises choosing a non-channelized toneselection if the determination is that at least one tone does notcontain critical information.
 7. The method of claim 6, furthercomprises selecting the tones randomly from a total number of tonesavailable, wherein the selection is based on at least one of systemtime, node identity, or combinations thereof.
 8. The method of claim 1,wherein the at least one tone that contains critical information is apilot tone for coherent demodulation.
 9. The method of claim 1, whereinselecting tones in the channel based on the determination is performedrandomly.
 10. A wireless communications apparatus, comprising: a memorythat retains instructions related to determining if at least one tonecontains critical information, selecting tones in a channel based on thedetermination, and transmitting on the selected tones in the channel;and a processor, coupled to the memory, configured to execute theinstructions retained in the memory.
 11. The wireless communicationsapparatus of claim 10, the memory further retains instructions relatedto choosing a channelized tone selection if the determination is that atleast one tone contains critical information.
 12. The wirelesscommunications apparatus of claim 11, wherein choosing a channelizedtone selection comprises selecting the channel from a set of pre-definedchannels, wherein each channel comprises at least one tone.
 13. Thewireless communications apparatus of claim 12, the memory furtherretains instructions related to selecting the tones randomly from afixed set of tones, wherein each tone comprises a channel.
 14. Acommunications apparatus, comprising: means for determining if at leastone tone contains critical information; means for selecting tones in achannel based on the determination; and means for transmitting on theselected tones in the channel.
 15. The communications apparatus of claim14, further comprising: means for choosing a channelized tone selectionif the determination is that at least one tone contains criticalinformation.
 16. The communications apparatus of claim 14, whereinchoosing a channelized tone selection comprises selecting the channelfrom a set of pre-defined channels, wherein each channel comprises atleast one tone.
 17. A computer program product, comprising; acomputer-readable medium comprising: a first set of codes for causing acomputer to determine if at least one tone contains criticalinformation; a second set of codes for causing the computer to selecttones in a channel based on the determination; and a third set of codesfor causing the computer to transmit on the selected tones in thechannel.
 18. The computer program product of claim 17, thecomputer-readable medium further comprising: a fourth set of codes forcausing the computer to choose a channelized tone selection if thedetermination is that at least one tone contains critical information,wherein choosing a channelized tone selection comprises selecting thechannel from a set of pre-defined channels, wherein each channelcomprises at least one tone.
 19. The computer program product of claim17, the computer-readable medium further comprising: a fourth set ofcodes for causing the computer to choose a non-channelized toneselection if the determination is that at least one tone does notcontain critical information.
 20. At least one processor configured toselect tones in a communication network comprising: a first module fordetermining if at least one tone contains critical information; a secondmodule for selecting tones in a channel based on the determination; anda third module for transmitting on the selected tones in the channel.21. A method for selecting tones in a communication network, comprising:receiving information related to a first channel used by at least oneneighboring device; selectively choosing at least one tone with asmallest interference and noise power based in part on the receivedinformation; using the at least one tone with the smallest interferenceand noise power to form a second channel; and selecting the secondchannel to communicate with at least one neighboring device within thecommunication network.
 22. The method of claim 21, wherein selectivelychoosing the at least one tone with the smallest interference and noisepower comprising: selecting the at least one tone that does not causeexcessive interference to the at least one neighboring device within thecommunication network.
 23. The method of claim 21, selectively choosingat least one tone with the smallest interference and noise power furthercomprising: identifying a symbol with the smallest total interferencepower; identifying one or more tones with the smallest interferencepower, the one or more tones are included in the identified symbol; andusing the identified one or more tones in the second channel.
 24. Themethod of claim 21, wherein the one or more identified tones are fromthe same symbol.
 25. The method of claim 21, further comprising:observing interference in the network; determining there is stronginterference experienced on the at least one tone used in the channel;and selectively changing the at least one tone used in the channel. 26.A wireless communications apparatus, comprising: a memory that retainsinstructions related to receiving information related to a first channelused by at least one neighboring device, selectively choosing at leastone tone with a smallest interference and noise power, using the atleast one tone with the smallest interference and noise power to form asecond channel, and selecting the second channel to communicate with theat least one neighboring device within the communication network; and aprocessor, coupled to the memory, configured to execute the instructionsretained in the memory.
 27. The wireless communications apparatus ofclaim 26, the memory further retains instructions related to selectingthe at least one tone that does not cause excessive interference to theat least one neighboring device within the communication network. 28.The wireless communications apparatus of claim 26, the memory furtherretains instructions related to identifying a symbol with the smallesttotal interference power, identifying one or more tones with thesmallest interference power, the one or more tones are included in theidentified symbol, and using the identified one or more tones in thesecond channel.
 29. The wireless communications apparatus of claim 26,the memory further retains instructions related to observinginterference in the network, determining if there is strong interferenceexperienced on the at least one tone used in the channel, andselectively changing the at least one tone used in the channel if stronginterference is experienced.
 30. A communications apparatus, comprising:means for receiving information related to a first channel used by atleast one neighboring device; means for choosing at least one tone witha smallest interference and noise power; means for using the at leastone tone with the smallest interference and noise power to form a secondchannel; and means for selecting the second channel to communicate withthe at least one neighboring device within the communication network.31. The communications apparatus of claim 30, wherein the means forchoosing at least one tone further selects the at least one tone thatdoes not cause excessive interference to the at least one neighboringdevice within the communication network.
 32. The communicationsapparatus of claim 30, wherein the means for choosing at least one tonefurther identifies a symbol with the smallest total interference power,identifies one or more tones with the smallest interference power, theone or more tones are included in the identified symbol and utilizes theidentified one or more tones in the second channel.
 33. Thecommunications apparatus of claim 30, wherein the one or more identifiedtones are from the same symbol.
 34. The communications apparatus ofclaim 30, further comprising: means for observing interference in thenetwork; means for determining there is strong interference experiencedon the at least one tone used in the channel; and means for selectivelychanging the at least one tone used in the channel.
 35. A computerprogram product, comprising: a computer-readable medium comprising: afirst set of codes for causing a computer to receive information relatedto a first channel used by at least one neighboring device; a second setof codes for causing the computer to choose at least one tone with asmallest interference and noise power; a third set of codes for causingthe computer to utilize the at least one tone with the smallestinterference and noise power to form a second channel; and a fourth setof codes for causing the computer to choose the second channel tocommunicate with the at least one neighboring device within thecommunication network.
 36. The computer program product of claim 35, thecomputer-readable medium further comprising: a fifth set of codes forcausing the computer to select the at least one tone that does not causeexcessive interference to the at least one neighboring device within thecommunication network.
 37. The computer program product of claim 35, thecomputer-readable medium further comprising: a fifth set of codes forcausing the computer to identify a symbol with the smallest totalinterference power; a sixth set of codes for causing the computer toidentify one or more tones with the smallest interference power, the oneor more tones are included in the identified symbol; and a seventh setof codes for causing the computer to utilize the identified one or moretones in the second channel.
 38. The computer program product of claim35, the computer-readable medium further comprising: a fifth set ofcodes for causing the computer to observe interference in the network; asixth set of codes for causing the computer to determine if there isstrong interference experienced on the at least one tone used in thechannel; and a seventh set of codes for causing the computer to changethe at least one tone used in the channel if strong interference isexperienced.
 39. At least one processor configured to provide toneselection, comprising: a first module for receiving information relatedto a first channel used by at least one neighboring device; a secondmodule for choosing at least one tone with a smallest interference andnoise power, wherein the at least one tone does not cause excessiveinterference to the at least one neighboring device within thecommunication network; a third module for using the at least one tonewith the smallest interference and noise power to form a second channel;and a fourth module for selecting the second channel to communicate withthe at least one neighboring device within the communication network.40. The at least one processor of claim 39, wherein the one or moreidentified tones are from different symbols.